1. Field of the Invention
The present invention relates to an information display panel, in which at least one group of display media having optical reflectance and charge characteristics, formed by at least one group of particles, are sealed in a cell (corresponding to one display unit) formed by partition walls between two substrates, at least one substrate being transparent, and, in which the display media, to which an electrostatic field is applied, are made to move so as to display information such as an image.
Moreover, the present invention relates to an information display panel, in which at least one group of display media having optical reflectance and charge characteristics, formed by at least one group of particles, are sealed in a cell (corresponding to one display unit) formed by partition walls between two substrates, at least one substrate being transparent, and, in which the display media, to which an electrostatic field is applied, are made to move so as to display information such as a color image.
2. Description of Related Art
As an information display device substitutable for liquid crystal display (LCD), information display devices with the use of technology such as an electrophoresis method, an electro-chromic method, a thermal method, dichroic-particles-rotary method are proposed.
As for these information display devices, it is conceivable as inexpensive visual display device of the next generation from a merit having wide field of vision close to normal printed matter, having smaller consumption with LCD, or having a memory function, and spreading out to a display for portable device and an electronic paper is expected. Recently, electrophoresis method is proposed that microencapsulate dispersion liquid made up with dispersion particles and coloration solution and dispose the liquid between faced substrates, and also it is expected.
However, in the electrophoresis method, there is a problem that a response rate is slow by the reason of viscosity resistance because the particles migrate among the electrophoresis solution. Further, there is a problem of lacking imaging repetition stability, because particles with high specific gravity of titanium oxide is scattered within solution of low specific gravity, it is easy to subside, difficult to maintain a stability of dispersion state. Even in the case of microencapsulating, cell size is diminished to a microcapsule level in order to make it hard to appear, however, an essential problem was not overcome at all.
Besides the electrophoresis method using behavior in the solution, recently, a method wherein electro-conductive particles and a charge transport layer are installed in a part of the substrate without using solution is proposed. [The Imaging Society of Japan “Japan Hardcopy '99” (Jul. 21-23, 1999) Transaction Pages 249-252] However, the structure becomes complicated because the charge transport layer and further a charge generation layer are to be arranged. In addition, it is difficult to constantly dissipate charges from the electro-conductive particles, and thus there is a drawback on the lack of stability.
As one method for overcoming the various problems mentioned above, an information display panel is known, in which at least one or more groups of display media having optical reflectance and charge characteristic, which are constituted by at least one of more groups of particles, are sealed between opposed two substrates, at least one substrate being transparent, and, in which the display media, to which an electrostatic field is applied, are made to move so as to display information such as an image.
In the known information display panel mentioned above, in order to perform a color display, it is thought about that use is made of for example white color and black color display media and a color filter formed by aligning filters having a predetermined number of Colors. For example, a color filter 51 formed by normally well-using red (R), green (G) and blue (B) filters constructs one display unit 52 by means of a red filter 51R, a green filter 51G and a blue filter 51B as shown in FIG. 19 as one example. Moreover, in order to improve a contrast of display color, a black matrix 53 having a black color is formed between respective filters. Therefore, in the known color filter 51 having the construction mentioned above, it is necessary to perform the process for forming the black matrix 53 between respective filters, and thus there are drawbacks such that a manufacturing process becomes complicated and a cost becomes high.
Moreover, as the another known examples of the information display panel in which a color display of information such as an image is performed, as shown in FIG. 20, there is known the information display panel, in which white color and black color display media (particles or liquid powders) 101W, 1010B are sealed in an air space of a cell 105 between a transparent substrate 103 at a display side, to which transparent color filters having three primary colors 102R, 102G, 102B are provided respectively and a substrate 104, and, in which the display media are moved to perform a color display of information such as an image (for example, referred to a pamphlet of International Publication WO2004/008239).
In the known information display panel mentioned above, in the case of using the white particles and the black particles as the display media, the color display is performed in such a manner that a reflection light from the white particles or the black particles is transmitted through the transparent color filters 102R, 102G, 102B and the transmitted lights are synthesized, and a colored layer 107 is arranged between a top of a partition wall 106 constituting one pixel and the substrate 103 and also between a partition wall 108 constituting respective cells 105 and the substrate 103. Therefore, it is possible to make a black density higher, but there is a drawback such that a display condition of a panel display surface becomes dark due to absorption of the transparent color filters.